Ball wheel



FIG. 1 is a perspective view of the ball wheel showing my new design;

FIG. 2 is a top plan view thereof, the bottom plan view being identical;

FIG. 3 is a front-side elevational view thereof, the rear-side elevational view, the right-side elevational view and the left-side elevational view being identical;

FIG. 4 is a perspective view of the ball wheel inside a housing;

FIG. 5 is a cross-sectional view taken along the line 5,6 of FIG. 2 showing a first configuration of the ball wheel comprising a hollow core; and,

FIG. 6 is a cross-sectional view taken along line 5,6 FIG. 2 showing an alternative configuration of the ball wheel comprising a solid core.

The broken lines depict portions of the article and environment that form no part of the claimed design. 

CLAIM The ornamental design for a ball wheel, as shown and described. 